Surgical stapler with rotary cam drive

ABSTRACT

A surgical circular stapler has a handle assembly, a shaft, a stapling assembly, a motor, a drive assembly, and a firing assembly. The shaft extends distally from the handle assembly. The stapling assembly is secured to a distal end of the shaft. Longitudinal translation of the firing assembly causes the stapling assembly to drive a plurality of staples in a circular array to secure two lumens of tissue together. The stapling assembly may further drive a blade to sever any excess tissue interior of the circular array of staples. The motor is operable to rotate the drive assembly to thereby translate the firing assembly. A resilient member biases the firing assembly proximally. Through cooperation between the firing assembly and the resilient member, the firing assembly is driven distally and proximally to complete a firing stroke in response to rotation of the drive assembly through a single revolution.

BACKGROUND

In some settings, a surgeon may want to position a surgical instrumentthrough an orifice of the patient and use the instrument to adjust,position, attach, and/or otherwise interact with tissue within thepatient. For instance, in some surgical procedures (e.g., colorectal,bariatric, thoracic, etc.), portions of the gastrointestinal tractand/or esophagus, etc. may be cut and removed to eliminate undesirabletissue or for other reasons. Once the desired tissue is removed, theremaining portions may need to be recoupled together in an end-to-endanastomosis. One such tool for accomplishing these anastomoticprocedures is a circular stapler that is inserted through a patient'snaturally occurring orifice. Some circular staplers are configured tosever tissue and staple tissue substantially simultaneously. Forinstance, a circular stapler may sever excess tissue that is interior toan annular array of staples at an anastomosis, to provide asubstantially smooth transition between lumen sections that are joinedat the anastomosis.

Examples of circular surgical staplers are described in U.S. Pat. No.5,205,459, entitled “Surgical Anastomosis Stapling Instrument,” issuedApr. 27, 1993; U.S. Pat. No. 5,271,544, entitled “Surgical AnastomosisStapling Instrument,” issued Dec. 21, 1993; U.S. Pat. No. 5,275,322,entitled “Surgical Anastomosis Stapling Instrument,” issued Jan. 4,1994; U.S. Pat. No. 5,285,945, entitled “Surgical Anastomosis StaplingInstrument,” issued Feb. 15, 1994; U.S. Pat. No. 5,292,053, entitled“Surgical Anastomosis Stapling Instrument,” issued Mar. 8, 1994; U.S.Pat. No. 5,333,773, entitled “Surgical Anastomosis Stapling Instrument,”issued Aug. 2, 1994; U.S. Pat. No. 5,350,104, entitled “SurgicalAnastomosis Stapling Instrument,” issued Sep. 27, 1994; and U.S. Pat.No. 5,533,6611, entitled “Surgical Anastomosis Stapling Instrument,”issued Jul. 9, 1996; and U.S. Pub. No. 2012/0292372, entitled “Low CostAnvil Assembly for a Circular Stapler,” published Nov. 22, 2012. Thedisclosure of each of the above-cited U.S. patents and U.S. PatentApplication Publication is incorporated by reference herein. Some suchstaplers are operable to clamp down on layers of tissue, cut through theclamped layers of tissue, and drive staples through the layers of tissueto substantially seal the severed layers of tissue together near thesevered ends of the tissue layers, thereby joining two severed ends ofan anatomical lumen.

Merely additional other exemplary surgical staplers are disclosed inU.S. Pat. No. 4,805,823, entitled “Pocket Configuration for InternalOrgan Staplers,” issued Feb. 21, 1989; U.S. Pat. No. 5,415,334, entitled“Surgical Stapler and Staple Cartridge,” issued May 16, 1995; U.S. Pat.No. 5,465,895, entitled “Surgical Stapler Instrument,” issued Nov. 14.1995; U.S. Pat. No. 5,597,107, entitled “Surgical Stapler Instrument,”issued Jan. 28, 1997; U.S. Pat. No. 5,632,432, entitled “SurgicalInstrument,” issued May 27, 1997; U.S. Pat. No. 5,673,840, entitled“Surgical Instrument,” issued Oct. 7, 1997; U.S. Pat. No. 5,704,534,entitled “Articulation Assembly for Surgical Instruments,” issued Jan.6, 1998; U.S. Pat. No. 5,814,055, entitled “Surgical ClampingMechanism,” issued Sep. 29, 1998; U.S. Pat. No. 6,978,921, entitled“Surgical Stapling Instrument Incorporating an E-Beam Firing Mechanism,”issued Dec. 27, 2005; U.S. Pat. No. 7,000,818, entitled “SurgicalStapling Instrument Having Separate Distinct Closing and FiringSystems,” issued Feb. 21, 2006; U.S. Pat. No. 7,143,923, entitled“Surgical Stapling Instrument Having a Firing Lockout for an UnclosedAnvil,” issued Dec. 5, 2006; U.S. Pat. No. 7,303,108, entitled “SurgicalStapling instrument Incorporating a Multi-Stroke Firing Mechanism with aFlexible Rack,” issued Dec. 4, 2007; U.S. Pat. No. 7,367,485, entitled“Surgical Stapling Instrument Incorporating a Multistroke FiringMechanism Having a Rotary Transmission,” issued May 6, 2008; U.S. Pat.No. 7,380,695, entitled “Surgical Stapling Instrument Having a SingleLockout Mechanism for Prevention of Firing,” issued Jun. 3, 2008; U.S.Pat. No. 7,380,696, entitled “Articulating Surgical Stapling InstrumentIncorporating a Two-Piece E-Beam Firing Mechanism,” issued Jun. 3, 2008;U.S. Pat. No. 7,404,508, entitled “Surgical Stapling and CuttingDevice,” issued Jul. 29, 2008; U.S. Pat. No. 7,434,715, entitled“Surgical Stapling Instrument Having Multistroke Firing with OpeningLockout,” issued Oct. 14, 2008; and U.S. Pat. No. 7,721,930, entitled“Disposable Cartridge with Adhesive for Use with a Stapling Device,”issued May 25, 2010. The disclosure of each of the above-cited U.S.patents is incorporated by reference herein. While the surgical staplersreferred to above are described as being used in endoscopic procedures,it should be understood that such surgical staplers may also be used inopen procedures and/or other non-endoscopic procedures.

While various kinds of surgical stapling instruments and associatedcomponents have been made and used, it is believed that no one prior tothe inventor(s) has made or used the invention described in the appendedclaims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a side elevation view of an exemplary circular staplingsurgical instrument;

FIG. 2A depicts an enlarged longitudinal cross-section view of anexemplary stapling head assembly of the instrument of FIG. 1 showing anexemplary anvil in an open position;

FIG. 2B depicts an enlarged longitudinal cross-sectional view of thestapling head assembly of FIG. 2A showing the anvil in a closedposition;

FIG. 2C depicts an enlarged longitudinal cross-sectional view of thestapling head assembly of FIG. 2A showing an exemplary staple driver andblade in a fired position;

FIG. 3 depicts an enlarged partial cross-sectional view of an exemplarystaple formed against the anvil;

FIG. 4A depicts an enlarged side elevation view of an exemplary actuatorhandle assembly of the surgical instrument of FIG. 1 with a portion ofthe body removed, showing a trigger in an unfired position and a lockoutfeature in a locked position;

FIG. 4B depicts an enlarged side elevation view of the actuator handleassembly of FIG. 4A, showing the trigger in a fired position and thelockout feature in an unlocked position;

FIG. 5 depicts an enlarged partial perspective view of an exemplaryindicator assembly of the surgical instrument of FIG. 1 showing anindicator window and indicator lever;

FIG. 6 depicts an diagrammatic view of the indicator window of FIG. 5showing an exemplary indicator bar and exemplary corresponding staplerepresentations;

FIG. 7 depicts a perspective view of an exemplary alternative circularstapling surgical instrument having a motor and exemplary multi-camassembly;

FIG. 8 depicts a side elevational view of the instrument, motor, andmulti-cam assembly of FIG. 7;

FIG. 9A depicts a side elevational view of the motor and multi-camassembly of FIG. 7 in a first rotational position;

FIG. 9B depicts a side elevational view of the motor and multi-camassembly of FIG. 7 in a second rotational position;

FIG. 9C depicts a side elevational view of the motor and multi-camassembly of FIG. 7 in a third rotational position;

FIG. 10A depicts a perspective view of the multi-cam assembly of FIG. 7in the first rotational position;

FIG. 10B depicts a perspective view of the multi-cam assembly of FIG. 7in the second rotational position;

FIG. 10C depicts a perspective view of the multi-cam assembly of FIG. 7in the third rotational position;

FIG. 11A depicts a side elevational view of an exemplary motor andsloped cam that may be incorporated into the instrument of FIG. 7, in afirst rotational position;

FIG. 11B depicts a side elevational view of the motor and sloped cam ofFIG. 11A in a second rotational position;

FIG. 12 depicts a perspective view of an exemplary alternative slopedcam that may be incorporated into the instrument of FIG. 7;

FIG. 13 depicts a perspective view of another exemplary alternativecircular stapling surgical instrument having a motor and cam;

FIG. 14 depicts a perspective view of the motor and earn of FIG. 13;

FIG. 15 depicts a front elevational view of the motor and cam of FIG.13;

FIG. 16A depicts a side elevational view of the instrument, motor, andcam of FIG. 13 in a first rotational position;

FIG. 16B depicts a side elevational view of the instrument, motor, andcam of FIG. 13 in a second rotational position;

FIG. 17 depicts a perspective view of the firing arm of the instrumentof FIG. 13;

FIG. 18 depicts a perspective view of an exemplary alternative firingarm that may be incorporated into the instrument of FIG. 13;

FIG. 19A depicts a side elevational view of an exemplary firing armassembly that ay be incorporated into the instrument of FIG. 13, in afirst position;

FIG. 19B depicts a side elevational view of the exemplary firing armassembly of FIG. 19A in a second position;

FIG. 20A depicts a side elevational view of another exemplary firing armassembly that may be incorporated into the instrument of FIG. 13, in afirst position;

FIG. 20B depicts a side elevational view of the exemplary firing armassembly of FIG. 20A in a second position;

FIG. 21 depicts a perspective view of an exemplary multi-motor firingassembly;

FIG. 22 depicts a side elevational view of an exemplary alternativecircular stapling surgical instrument having an obliquely orientedmotor;

FIG. 23 depicts a perspective view of another exemplary alternativecircular stapling surgical instrument having an obliquely orientedmotor; and

FIG. 24 depicts an exemplary force profile associated with a firingstroke for a circular stapling surgical instrument.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

I. Overview of Exemplary Circular Stapling Surgical Instrument

FIGS. 1-6 depict an exemplary circular surgical stapling instrument (10)having a stapling head assembly (20), a shaft assembly (60), and anactuator handle assembly (70), each of which will be described in moredetail below. Shaft assembly (60) extends distally from actuator handleassembly (70) and stapling head assembly (20) is coupled to a distal endof shaft assembly (60). In brief, actuator handle assembly (70) isoperable to actuate a staple driver (24) of stapling head assembly (20)to drive a plurality of staples (66) out of stapling head assembly (20).Staples (66) are bent to form completed staples by an anvil (40) that isattached at the distal end of instrument (10). Accordingly, tissue (2),shown in FIGS. 2A-2C, may be stapled utilizing instrument (10).

In the present example, instrument (10) comprises a closure system and afiring system. The closure system comprises a trocar (38), a trocaractuator (39), and a rotating knob (98). An anvil (40) may be coupled toa distal end of trocar (38). Rotating knob (98) is operable tolongitudinally translate trocar (38) relative to stapling head assembly(20), thereby translating anvil (40) when anvil (40) is coupled totrocar (38), to clamp tissue between anvil (40) and stapling headassembly (20). The firing system comprises a trigger (74), a triggeractuation assembly (84), a driver actuator (64), and a staple driver(24). Staple driver (24) includes a knife (36) configured to severtissue when staple driver (24) is actuated longitudinally. In addition,staples (66) are positioned distal to a plurality of staple drivingfeatures (30) of staple driver (24) such that staple driver (24) alsodrives staples (66) distally when staple driver (24) is actuatedlongitudinally. Thus, when trigger (74) is actuated and triggeractuation assembly (84) actuates staple driver (24) via driver actuator(64), knife (36) and members (30) substantially simultaneously severtissue (2) and drive staples (66) distally relative to stapling headassembly (20) into tissue. The components and functionalities of theclosure system and firing system will now be described in greaterdetail.

A. Exemplary Anvil

As shown in FIGS. 1-2C, anvil (40) is selectively coupleable toinstrument (10) to provide a surface against which staples (66) may bebent to staple material contained between stapling head assembly (20)and anvil (40). Anvil (40) of the present example is selectivelycoupleable to a trocar or pointed rod (38) that extends distallyrelative to stapling head assembly (20). Referring to FIGS. 2A-2C, anvil(40) is selectively coupleable via the coupling of a proximal shaft (42)of anvil (40) to a distal tip of trocar (38). Anvil (40) comprises agenerally circular anvil head (48) and a proximal shaft (42) extendingproximally from anvil head (48). In the example shown, proximal shaft(42) comprises a tubular member (44) having resiliently biased retainingclips (46) to selectively couple anvil (40) to trocar (38), though thisis merely optional, and it should be understood that other retentionfeatures for coupling anvil (40) to trocar (38) may be used as well. Forexample, C-clips, clamps, threading, pins, adhesives, etc. may beemployed to couple anvil (40) to trocar (38). In addition, while anvil(40) is described as selectively coupleable to trocar (38), in someversions proximal shaft (42) may include a one-way coupling feature suchthat anvil (40) cannot be removed from trocar (38) once anvil (40) isattached. Merely exemplary one-way features include barbs, one waysnaps, collets, collars, tabs, bands, etc. Of course still otherconfigurations for coupling anvil (40) to trocar (38) will be apparentto one of ordinary skill in the art in view of the teachings herein. Forinstance, trocar (38) may instead be a hollow shaft and proximal shaft(42) may comprise a sharpened rod that is insertable into the hollowshaft.

Anvil head (48) of the present example comprises a plurality of stapleforming pockets (52) formed in a proximal face (50) of anvil head (48).Accordingly, when anvil (40) is in the closed position and staples (66)are driven out of stapling head assembly (20) into staple formingpockets (52), as shown in FIG. 2C, legs (68) of staples (66) are bent toform completed staples.

With anvil (40) as a separate component, it should be understood thatanvil (40) may be inserted and secured to a portion of tissue (2) priorto being coupled to stapling head assembly (20). By way of example only,anvil (40) may be inserted into and secured to a first tubular portionof tissue (2) while instrument (10) is inserted into and secured to asecond tubular portion of tissue (2). For instance, the first tubularportion of tissue (2) may be sutured to or about a portion of anvil(40), and the second tubular portion of tissue (2) may be sutured to orabout trocar (38).

As shown in FIG. 2A, anvil (40) is then coupled to trocar (38). Trocar(38) of the present example is shown in a distal most actuated position.Such an extended position for trocar (38) may provide a larger area towhich tissue (2) may be coupled prior to attachment of anvil (40). Inaddition, the extended position of trocar (38) may also provide foreasier attachment of anvil (40) to trocar (38). Trocar (38) furtherincludes a tapered distal tip. Such a tip may be capable of piercingthrough tissue and/or aiding the insertion of anvil (40) on to trocar(38), though the tapered distal tip is merely optional. For instance, inother versions trocar (38) may have a blunt tip. In addition, or in thealternative, trocar (38) may include a magnetic portion (not shown)which may attract anvil (40) towards trocar (38). Of course stillfurther configurations and arrangements for anvil (40) and trocar (38)will be apparent to one of ordinary skill in the art in view of theteachings herein.

When anvil (40) is coupled to trocar (38), the distance between aproximal face of the anvil (40) and a distal face of stapling headassembly (20) defines a gap distance d. Trocar (38) of the presentexample is translatable longitudinally relative to stapling headassembly (20) via an adjustment knob (98) located at a proximal end ofactuator handle assembly (70), as will be described in greater detailbelow. Accordingly, when anvil (40) is coupled to trocar (38), rotationof adjustment knob (98) enlarges or reduces gap distance d by actuatinganvil (40) relative to stapling head assembly (20). For instance, asshown sequentially in FIGS. 2A-2B, anvil (40) is shown actuatingproximally relative to actuator handle assembly (70) from an initial,open position to a closed position, thereby reducing the gap distance dand the distance between the two portions of tissue (2) to be joined.Once the gap distance d is brought within a predetermined range,stapling head assembly (20) may be fired, as shown in FIG. 2C, to stapleand sever tissue (2) between anvil (40) and stapling head assembly (20).Stapling head assembly (20) is operable to staple and sever tissue (2)by a user pivoting a trigger (74) of actuator handle assembly (70), aswill be described in greater detail below.

As noted above, gap distance d corresponds to the distance between anvil(40) and stapling head assembly (20). When instrument (10) is insertedinto a patient, this gap distance d may not be easily viewable.Accordingly, a moveable indicator bar (110), shown in FIGS. 5-6, isprovided to be visible through an indicator window (120) positionedopposite to trigger (74). Indicator bar (110) is operable to move inresponse to rotation of adjustment knob (98) such that the position ofindicator bar (110) is representative of the gap distance d. As shown inFIG. 6, indicator window (120) further comprises a scale (130) whichindicates that the anvil gap is within a desired operating range (e.g.,a green colored region or “green zone”) and a corresponding staplecompression representation at each end of scale (130). By way of exampleonly, as shown in FIG. 6, a first staple image (132) depicts a largestaple height while a second staple image (134) depicts a small stapleheight. Accordingly, a user can view the position of the coupled anvil(40) relative to the stapling head assembly (20) via indicator bar (110)and scale (130). The user may then adjust the positioning of anvil (40)via adjustment knob (98) accordingly.

Referring back to FIGS. 2A-2C, a user sutures a portion of tissue (2)about tubular member (44) such that anvil head (48) is located within aportion of the tissue (2) to be stapled. When tissue (2) is attached toanvil (40), retaining clips (46) and a portion of tubular member (44)protrude out from tissue (2) such that the user may couple anvil (40) totrocar (38). With tissue (2) coupled to trocar (38) and/or anotherportion of stapling head assembly (20), the user attaches anvil (40) totrocar (38) and actuates anvil (40) proximally towards stapling headassembly (20) to reduce the gap distance d. Once instrument (10) iswithin the operating range, the user then staples together the ends oftissue (2), thereby forming a substantially contiguous tubular portionof tissue (2).

Anvil (40) may be further constructed in accordance with at least someof the teachings of U.S. Pat. No. 5,205,459; U.S. Pat. No. 5,271,544;U.S. Pat. No. 5,275,322; U.S. Pat. No. 5,285,945; U.S. Pat. No.5,292,053; U.S. Pat. No. 5,333,773; U.S. Pat. No. 5,350,104; U.S. Pat.No. 5,533,661; and/or U.S. Pub. No. 2012/0292372, the disclosures ofwhich are incorporated by reference herein; and/or in accordance withother configurations as will be apparent to one of ordinary skill in theart in view of the teachings herein.

B. Exemplary Stapling Head Assembly

Stapling head assembly (20) of the present example is coupled to adistal end of shaft assembly (60) and comprises a tubular casing (22)housing a slidable staple driver (24) and a plurality of staples (66)contained within staple pockets (32). Staples (66) and staple pockets(32) are disposed in a circular array about tubular casing (22). In thepresent example, staples (66) and staple pockets (32) are disposed in apair of concentric annular rows of staples (66) and staple pockets (32).Staple driver (24) is operable to actuate longitudinally within tubularcasing (22) in response to rotation of trigger (74) of actuator handleassembly (70). As shown in FIGS. 2A-2C, staple driver (24) comprises aflared cylindrical member having a trocar opening (26), a central recess(28), and a plurality of members (30) disposed circumferentially aboutcentral recess (28) and extending distally relative to shaft assembly(60). Each member (30) is configured to contact and engage acorresponding staple (66) of the plurality of staples (66) within staplepockets (32). Accordingly, when staple driver (24) is actuated distallyrelative to actuator handle assembly (70), each member (30) drives acorresponding staple (66) out of its staple pocket (32) through a stapleaperture (34) formed in a distal end of tubular casing (22). Becauseeach member (30) extends from staple driver (24), the plurality ofstaples (66) are driven out of stapling head assembly (20) atsubstantially the same time. When anvil (40) is in the closed position,staples (66) are driven into staple forming pockets (52) to bend legs(68) of the staples (66), thereby stapling the material located betweenanvil (40) and stapling head assembly (20). FIG. 3 depicts one merelyexemplary staple (66) driven by a member (30) into a staple formingpocket (32) of anvil (40) to bend legs (68).

Staple driver (24) further includes a cylindrical knife (36) that iscoaxial to trocar opening (26) and inset from staple pockets (32). Inthe present example, cylindrical knife (36) is disposed within centralrecess (28) to translate distally with staple driver (24). When anvil(40) is secured to trocar (38), as described above, anvil head (48)provides a surface against which cylindrical knife (36) cuts thematerial contained between anvil (40) and stapling head assembly (20).In some versions, anvil head (48) may include a recess (not shown) forcylindrical knife (36) to aid in cutting the material (e.g., byproviding a cooperative shearing edge). In addition, or in thealternative, anvil head (48) may include one or more opposingcylindrical knives (not shown) offset from cylindrical knife (36) suchthat a scissor-type cutting action may be provided. Still otherconfigurations will be apparent to one of ordinary skill in the art inview of the teachings herein. Stapling head assembly (20) is thusoperable to both staple and cut tissue (2) substantially simultaneouslyin response to actuation by actuator handle assembly (70).

Of course stapling head assembly (20) may be further constructed inaccordance with at least some of the teachings of U.S. Pat. No.5,205,459; U.S. Pat. No. 5,271,544; U.S. Pat. No. 5,275,322; U.S. Pat.No. 5,285,945; U.S. Pat. No. 5,292,053; U.S. Pat. No. 5,333,773; U.S.Pat. No. 5,350,104; U.S. Pat. No. 5,533,661; and/or U.S. Pub. No.2012/0292372, the disclosures of which are incorporated by referenceherein; and/or in accordance with other configurations as will beapparent to one of ordinary skill in the art in view of the teachingsherein.

As noted previously, staple driver (24) includes a trocar opening (26).Trocar opening (26) is configured to permit trocar (38) tolongitudinally slide relative to stapling head assembly (20) and/orshaft assembly (60). As shown in FIGS. 2A-2C, trocar (38) is coupled toa trocar actuator (39) such that trocar (38) can be actuatedlongitudinally via rotation of rotating knob (98), as will be describedin greater detail below in reference to actuator handle assembly (70).In the present example, trocar actuator (39) comprises an elongated,relatively stiff shaft coupled to trocar (38), though this is merelyoptional. In some versions, actuator (39) may comprise a longitudinallystiff material while permitting lateral bending such that portions ofinstrument (10) may be selectively bent or curved during use; orinstrument (10) may include a preset bent shaft assembly (60). Whenanvil (40) is coupled to trocar (38), trocar (38) and anvil (40) aretranslatable via actuator (39) to adjust the gap distance d betweenanvil (40) and stapling head assembly (20). Still further configurationsfor actuator (39) to longitudinally actuate trocar (38) will be apparentto one of ordinary skill in the art in view of the teachings herein.

C. Exemplary Shaft Assembly

Stapling head assembly (20) and trocar (38) are positioned at a distalend of shaft assembly (60), as shown in FIGS. 2A-2C. Shaft assembly (60)of the present example comprises an outer tubular member (62) and adriver actuator (64). Outer tubular member (62) is coupled to tubularcasing (22) of stapling head assembly (20) and to a body (72) ofactuator handle assembly (70), thereby providing a mechanical ground forthe actuating components therein. The proximal end of driver actuator(64) is coupled to a trigger actuation assembly (84) of actuator handleassembly (70), described below. The distal end of driver actuator (64)is coupled to staple driver (24) such that the rotation of trigger (74)longitudinally actuates staple driver (24). As shown in FIGS. 2A-2C,driver actuator (64) comprises a tubular member having an openlongitudinal axis such that actuator (39) coupled to trocar (38) mayactuate longitudinally within and relative to driver actuator (64). Ofcourse it should be understood that other components may be disposedwithin driver actuator (64) as will be apparent to one of ordinary skillin the art in view of the teachings herein.

Shaft assembly (60) may be further constructed in accordance with atleast some of the teachings of U.S. Pat. No. 5,205,459; U.S. Pat. No.5,271,544; U.S. Pat. No. 5,275,322; U.S. Pat. No. 5,285,945; U.S. Pat.No, 5,292,053; U.S. Pat. No, 5,333,773; U.S. Pat. No. 5,350,104; U.S.Pat. No. 5,533,661; and/or U.S. Pub. No. 2012/0292372, the disclosuresof which are incorporated by reference herein; and/or in accordance withother configurations as will be apparent to one of ordinary skill in theart in view of the teachings herein.

D. Exemplary Actuator Handle Assembly

Referring now to FIGS. 4A-5, actuator handle assembly (70) comprises abody (72), a trigger (74), a lockout feature (82), a trigger actuationassembly (84), and a trocar actuation assembly (90). Trigger (74) of thepresent example is pivotably mounted to body (72) and is coupled totrigger actuation assembly (84) such that rotation of trigger (74) froman unfired position (shown in FIG. 4A) to a fired position (shown inFIG. 4B) actuates driver actuator (64) described above. A spring (78) iscoupled to body (72) and trigger (74) to bias trigger (74) towards theunfired position. Lockout feature (82) is a pivotable member that iscoupled to body (72). In a first, locked position, lockout feature (82)is pivoted upwards and away from body (72) such that lockout feature(82) engages trigger (74) and mechanically resists actuation of trigger(74) by a user. In a second, unlocked position, such as that shown inFIGS. 1 and 4B, lockout feature (82) is pivoted downward such thattrigger (74) may be actuated by the user. Accordingly, with lockoutfeature (82) in the second position, trigger (74) can engage a triggeractuation assembly (84) to fire instrument (10).

As shown in FIGS. 4A-4B, trigger actuation assembly (84) of the presentexample comprises a slidable trigger carriage (86) engaged with aproximal end of driver actuator (64). Carriage (86) includes a set oftabs (88) on a proximal end of carriage (86) to retain and engage a pairof trigger arms (76) extending from trigger (74). Accordingly, whentrigger (74) is pivoted, carriage (86) is actuated longitudinally andtransfers the longitudinal motion to driver actuator (64). In theexample shown, carriage (86) is fixedly coupled to the proximal end ofdriver actuator (64), though this is merely optional. Indeed, in onemerely exemplary alternative, carriage (86) may simply abut driveractuator (64) while a distal spring (not shown) biases driver actuator(64) proximally relative to actuator handle assembly (70).

Trigger actuation assembly (84) may be further constructed in accordancewith at least some of the teachings of U.S. Pat. No. 5,205,459; U.S.Pat. No. 5,271,544 U.S. Pat. No. 5,275,322; U.S. Pat. No. 5,285,945;U.S. Pat. No. 5,292,053; U.S. Pat. No. 5,333,773; U.S. Pat. No.5,350,104; U.S. Pat. No. 5,533,661; and/or U.S. Pub. No. 2012/0292372,the disclosures of which are incorporated by reference herein; and/or inaccordance with other configurations as will be apparent to one ofordinary skill in the art in view of the teachings herein.

Body (72) also houses a trocar actuation assembly (90) configured toactuate trocar (38) longitudinally in response to rotation of adjustmentknob (98). As best shown in FIGS. 4A-5, trocar actuation assembly (90)of the present example comprises adjustment knob (98), a grooved shank(94), and a sleeve (92). Grooved shank (94) of the present example islocated at a proximal end of trocar actuator (39), though it should beunderstood that grooved shank (94) and trocar actuator (39) mayalternatively be separate components that engage to transmitlongitudinal movement. While grooved shank (94) is configured totranslate within body (72), grooved shank (94) does not rotate withinbody (72). Adjustment knob (98) is rotatably supported by the proximalend of body (72) and is operable to rotate sleeve (92), which is engagedwith grooved shank (94) via an internal tab (not shown). Adjustment knob(98) also defines internal threading (not shown) as will be described ingreater detail below. Grooved shank (94) of the present examplecomprises a continuous groove (96) formed in the outer surface ofgrooved shank (94). Accordingly, when adjustment knob (98) is rotated,the internal tab of sleeve (92) rides within groove (96) and groovedshank (94) is longitudinally actuated relative to sleeve (92). Sincegrooved shank (94) is located at the proximal end of trocar actuator(39), rotating adjustment knob (98) in a first direction advances trocaractuator (39) distally relative to actuator handle assembly (70).Accordingly, the gap distance d between anvil (40) and stapling headassembly (20) is increased. By rotating adjustment knob (98) in theopposite direction, trocar actuator (39) is actuated proximally relativeto actuator handle assembly (70) to reduce the gap distance d betweenanvil (40) and stapling head assembly (20). Thus, trocar actuationassembly (90) is operable to actuate trocar (38) in response to rotatingadjustment knob (98). Of course other configurations for trocaractuation assembly (90) will be apparent to one of ordinary skill in theart in view of the teachings herein.

Groove (96) of the present example comprises a plurality of differentportions (96A, 96B, 96C) that have a varying pitch or number of groovesper axial distance. The present groove (96) is divided into a distalportion (96A), a middle portion (96B) and a proximal portion (96C). Asshown in FIG. 5, distal portion (96A) comprises a fine pitch or a highnumber of grooves over a short axial length of grooved shank (94).Middle portion (96B) comprises a section with comparably coarser pitchor fewer grooves per axial length such that relatively few rotations arerequired for the internal tab of sleeve (92) to traverse a long axialdistance. When anvil (40) is in an initial, distal position in relationto stapling head assembly (20), the internal tab of sleeve (92) ispositioned in middle portion (96B). Accordingly, the gap distance d maybe quickly reduced through relatively few rotations of adjustment knob(98) while the internal tab of sleeve (92) traverses middle portion(96B). Proximal portion (96C) of the present example is substantiallysimilar to distal portion (96A) and comprises a fine pitch or a highnumber of grooves over a short axial distance of grooved shank (94) suchthat a large number of rotations are required to traverse the shortaxial distance. Proximal portion (96C) of the present example is engagedby the internal threading defined by knob (98) when anvil (40) issubstantially near to stapling head assembly (20), such that indicatorbar (110) moves within indicator window (120) along scale (130) toindicate that the anvil gap is within a desired operating range, as willbe described in more detail below. Accordingly, when grooved shank (94)reaches a proximal position where the proximal portion (96C) of groove(96) engages the internal threading of knob (98), each rotation ofadjustment knob (98) may reduce the gap distance d by a relatively smallamount to provide for fine tuning. It should be understood that theinternal tab of sleeve (92) may be disengaged from groove (96) whenproximal portion (96C) is engaged with the internal threading of knob(98).

Trocar actuation assembly (90) may be further constructed in accordancewith at least some of the teachings of U.S. Pat. No. 5,205,459; U.S.Pat. No. 5,271,544; U.S. Pat. No. 5,275,322; U.S. Pat. No. 5,285,945;U.S. Pat. No. 5,292,053; U.S. Pat. No. 5,333,773; U.S. Pat. No.5,350,104; U.S. Pat. No. 5,533,661, the disclosures of which areincorporated by reference herein; and/or in accordance with otherconfigurations as will be apparent to one of ordinary skill in the artin view of the teachings herein.

In the example shown in FIGS. 4A-4B, a U-shaped clip (100) is attachedto an intermediate portion of trocar actuator (39) located distally ofgrooved shank (94). In the present example, an extension of trocaractuator (39) engages a slot in the housing of handle assembly (70) toprevent trocar actuator (39) from rotating about its axis whenadjustment knob (98) is rotated. U-shaped clip (100) of the presentexample further includes an elongated slot (102) on each of its oppositesides for receiving an attachment member, such as a screw, bolt, pin,etc., to selectively adjust the longitudinal position of elongated slot(102) of U-shaped clip (100) relative to trocar actuator (39) forpurposes of calibrating indicator bar (110) relative to scale (130). Insome versions, the attachment member (e.g., screw, bolt, pin, etc.)engages with a portion of body (72) to substantially prevent trocaractuator (39) from rotating about its axis when adjustment knob (98) isrotated.

As shown in FIG. 5, actuator handle assembly (70) further includes anindicator bracket (140) configured to engage and pivot an indicator(104). Indicator bracket (140) of the present example is slidablerelative to body (72) along a pair of slots formed on body (72).Indicator bracket (140) comprises a rectangular plate (144), anindicator arm (146), and an angled flange (142). Angled flange (142) isformed at the proximal end of rectangular plate (144) and includes anaperture (not shown) to slidable mount onto trocar actuator (39) and/orgrooved shank (94). A coil spring (150) is interposed between flange(142) and a boss (152) to bias flange (142) against U-shaped clip (100).Accordingly, when U-shaped clip (100) actuates distally with trocaractuator (39) and/or grooved shank (94), coil spring (150) urgesindicator bracket (140) to travel distally with U-shaped clip (100). Inaddition, U-shaped clip (100) urges indicator bracket (140) proximallyrelative to boss (152) when trocar actuator (39) and/or grooved shank(94) translate proximally, thereby compressing coil spring (150). Ofcourse, it should be understood that in some versions indicator bracket(140) may be fixedly attached to trocar actuator (39) and/or groovedshank (94).

In the present example, a portion of lockout feature (82) abuts asurface (141) of indicator bracket (140) when indicator bracket (140) isin a longitudinal position that does not correspond to when the anvilgap is within a desired operating range (e.g., a green colored region or“green zone”). When the anvil gap is within a desired operating range(e.g., a green colored region or “green zone”), indicator bracket (140)narrows to provide a pair of gaps (145) on either side of an indicatorarm (146) that permits lockout feature (82) to pivot, thereby releasingtrigger (74). Accordingly, lockout feature (82) and indicator bracket(140) can substantially prevent a user from releasing and operatingtrigger (74) until anvil (40) is in a predetermined operating range. Ofcourse it should be understood that lockout feature (82) may be omittedentirely in some versions.

This operating range may be visually communicated to the user via anindicator bar (110) of an indicator (104) shown against a scale (130),described briefly above. At the distal end of indicator bracket (140) isa distally projecting indicator arm (146) which terminates at alaterally projecting finger (148) for controlling the movement ofindicator (104). Indicator arm (146) and finger (148), best shown inFIG. 5, are configured to engage a tab (106) of indicator (104) suchthat indicator (104) is pivoted when indicator bracket (140) is actuatedlongitudinally. In the present example, indicator (104) is pivotablycoupled to body (72) at a first end of indicator (104), though this ismerely optional. and other pivot points for indicator (104) will beapparent to one of ordinary skill in the art in view of the teachingsherein. An indicator bar (110) is positioned on the second end ofindicator (104) such that indicator bar (110) moves in response to theactuation of indicator bracket (140). Accordingly, as discussed above,indicator bar (110) is displayed through an indicator window (120)against a scale (130) (shown in FIG. 6) to show the relative gapdistance d between anvil (40) and stapling head assembly (20).

Of course indicator bracket (140), indicator (104), and/or actuatorhandle assembly (70) may be further constructed in accordance with atleast some of the teachings of U.S. Pat, No. 5,205,459; U.S. Pat. No,5,271,544; U.S. Pat. No. 5,275,322; U.S. Pat. No. 5,285,945; U.S. Pat.No. 5,292,053; U.S. Pat. No. 5,333,773; U.S. Pat. No. 5,350,104; U.S.Pat. No. 5,533,661; and/or U.S. Pub. No. 2012/0292372, the disclosuresof which are incorporated by reference herein; and/or in accordance withother configurations as will be apparent to one of ordinary skill in theart in view of the teachings herein.

II. Exemplary Motorized Circular Surgical Stapling Instrument withTranslating Cam Follower

In some instances, it may be desirable to drive staples (66) and knife(36) in a way that avoids manually driving circular surgical staplinginstrument (10). For instance, in the event that the operator hasinadequate hand strength to actuate circular surgical staplinginstrument (10), it may be desirable to provide a motorized assembly forstaple driver (24) and knife (36). Motorizing at least part ofinstrument (10) may also reduce the risk of operator error in drivingstaple driver (24) and knife (36). In some cases, operator error with amanually driven instrument (10) may result in instrument (10) failing toactuate fully. This may occur when an operator fails to fully manuallyactuate trigger (74), which may result in staples (66) not fully formingand thus not fully securing an anastomsis. Thus, motorizing the drivingof staple driver (24) and knife (36) may ensure that knife (36) is fullydriven to cut tissue, and that staples (66) are fully deployed to fastentissue, in a single drive stroke. Various examples of how instrument(10) may be reconfigured to incorporate a motor will be described ingreater detail below; while other examples will be apparent to those ofordinary skill in the art according to the teachings herein. It shouldbe understood that the examples described below may functionsubstantially similar to instrument (10) described above. In particular,the circular surgical stapling instruments described below may be usedto staple tissue in an annular array and sever excess tissue that isinterior to the annular array of staples to provide a substantiallysmooth transition between lumen sections.

While it may be desirable to at least partially motorize circularsurgical stapling instrument (10), it may not necessarily be desirableto motorize all portions of circular surgical stapling instrument (10).For instance, it may be desirable to maintain manual adjustment of knob(98) or a similar feature to control the distance d between anvil (40)and stapling head assembly (20). Other suitable portions of circularsurgical stapling instrument (10) may also rely on manual actuationdespite motorization of other features, as will be apparent to those ofordinary skill in the art in view of the teachings herein.

One merely exemplary variation of a motorized circular surgical staplinginstrument (200) is shown in FIG. 7. Instrument (200) of the presentexample comprises a closure system and a firing system. The closuresystem of the present example comprises a rotating knob (298), which isoperable to drive an anvil (240). Closure system and knob (298) of thepresent example function substantially similar to the closure system andknob (98) of instrument (10) described above. In particular, knob (298)may be rotated to longitudinally actuate a trocar actuator (239) toenlarge or reduce a gap distance between a proximal face of an anvil(240) and a distal face of a stapling head assembly (218).

The firing system of the present example functions substantially similarto the firing system of instrument (10) described above except for thedifferences discussed below. In particular, the firing system of thepresent example may be used to actuate a staple driver and knife (notshown). The firing system of the present example comprises a motor(210), a follower interface feature (284), a driver actuator (264), astaple driver (e.g., like staple driver (24) described above), and aknife (e.g., like knife (36) described above). Driver actuator (264) ofthe present example is configured to operate substantially similar todriver actuator (64) of instrument (10) discussed above. In particular,a distal end of driver actuator (264) is coupled with the staple driverand knife such that actuation of motor (210) longitudinally translatesdriver actuator (264), which in turn longitudinally actuates the stapledriver and knife. Motor (210) of the present example is powered via abattery pack (212), though it should be understood that motor (210) maybe powered by any other appropriate power source including an externalpower source (e.g. a wall outlet, etc.). As will be discussed in moredetail below, motor (210) is operable to actuate stapling head assembly(218). In the present example, motor (210) is oriented along an axisthat is parallel to the longitudinal axis defined by driver actuator(264). However, it should be understood that motor (210) may instead beoriented obliquely relative to the longitudinal axis defined by driveractuator (264). By way of example only, a merely illustrative obliquemotor orientation is described in greater detail below with reference toFIGS. 22-23.

Stapling head assembly (218) includes the staple driver, a plurality ofstaples, and the knife, which is configured to sever tissue when thestaple driver is actuated longitudinally. Stapling head assembly (218)of the present example functions substantially similar to stapling headassembly (20) described above except for the differences discussedbelow. In particular, stapling head assembly (218) of the presentexample may be used to drive an annular array of staples into tissue andto drive the knife to sever excess tissue that is interior to theannular array of staples to provide a substantially smooth transitionbetween lumen sections in response to actuation of the staple driver. Aproximal end of driver actuator (264) is coupled with follower interfacefeature (284) of an actuator handle assembly (270). A distal end ofdriver actuator (264) is coupled to the staple driver and knife suchthat longitudinal translation of follower interface feature (284)actuates the staple driver and knife, As will be discussed in moredetail below, motor (210) is operable to cause longitudinal translationof follower interface feature (284) via a drive assembly. Thus, whenmotor (210) is actuated, follower interface feature (284) actuates thestaple driver and the knife via driver actuator (264) to substantiallysimultaneously sever tissue and drive staples distally into the tissue.

As shown in FIG. 7, motor (210) is in communication with an operatorinput (202). Operator input (202) may include a manually actuatedtrigger (e.g., similar to trigger (74), etc.) and/or some other inputoperable to activate motor (210). For instance, operator input (202)could include a button, trigger, lever, slider, touchpad, etc. thatelectrically activates motor (210). In addition or in the alternative,operator input (202) may include an electrical or software drivenactuator operated by the operator to activate motor (210). In someversions, operator input (202) may include a foot actuated pedal incommunication with motor (210). Other suitable forms that operator input(202) may take will be apparent to those of ordinary skill in the art inview of the teachings herein.

It will also be understood that operator input (202) may be placed inany appropriate position on or relative to circular surgical staplinginstrument (10) as will be apparent to one of ordinary skill in the artin view of the teachings herein. For instance, operator input (202) maybe positioned on any portion of actuator handle assembly (70) as seen inFIG. 1. Alternatively, operator input (202) may also be positionedsomewhere separately from circular surgical stapling instrument (10),which may include locating operator input (202) on a separate console orcomputer, Operator input (202) could also be located on a console ordevice in wireless communication with circular surgical staplinginstrument (10). Other suitable locations for operator input (202) willbe apparent to those of ordinary skill in the art in view of theteachings herein.

A. First Exemplary Motor and Drive Assembly with Translating CamFollower

As shown in FIG. 8, motor (210) is disposed within actuator handleassembly (270) parallel to a proximal portion of driver actuator (264).A multi-cam assembly (220) is coupled with a distal end of motor (210).Motor (210) is operable to cause rotation of multi-cam assembly (220)about a longitudinal axis (LAI) defined by motor (210). As best seen inFIGS. 9A-10C, multi-cam assembly (220) comprises a shaft (222) and apair of cams (230, 240) mounted eccentrically on shaft (222) atdifferent longitudinal positions along longitudinal axis (LA1). In thepresent example, the housing of handle assembly (270) provides simplesupport to shaft (222) and the remainder of multi-cam assembly (220).Alternatively, shaft (222) and the remainder of multi-cam assembly (220)may receive support in any other suitable fashion and/or from any othersuitable component(s).

As shown in FIGS. 10A-10C, an exterior surface of first cam (230)comprises a first portion (232) and a second portion (234). Firstportion (232) and second portion (234) are disposed on radially oppositesides of first cam (230). First portion (232) presents a portion offirst cam (230) having a radial distance from longitudinal axis (LA1)that is greater than a radial distance of second portion (234) fromlongitudinal axis (LA1), First cam (230) further comprises intermediateportions (233, 235) disposed between first portion (232) and secondportion (234), Intermediate portions (233, 235) are contoured to providesubstantially smooth transition between first portion (232) and secondportion (234) along radially opposite sides of first cam (230). Thus, ata particular point along an exterior surface of first cam (230), asfirst cam (230) is rotated through one revolution, a radial distancefrom first cam (230) to longitudinal axis (LA1) will change from thegreater radial distance presented by first portion (232); to the lesserradial distance presented by second portion (234) via intermediateportion (233); and back to the greater radial distance presented byfirst portion (232) via intermediate portion (235).

As also shown in FIGS. 10A-10C, an exterior surface of second cam (240)comprises a first portion (242) and a second portion (244). Firstportion (242) and second portion (244) are disposed on radially oppositesides of second cam (240). First portion (242) presents a portion ofsecond cam (240) having a radial distance from longitudinal axis (LA1)that is greater than a radial distance of second portion (244) fromlongitudinal axis (LA1). Second cam (240) further comprises intermediateportions (243, 245) disposed between first portion (242) and secondportion (244). Intermediate portions (243, 245) are contoured to providesubstantially smooth transition between first portion (242) and secondportion (244) along radially opposite sides of second cam (240). Thus,at a particular point along an exterior surface of second cam (240), assecond cam (240) is rotated through one revolution, a radial distancefrom second cam (240) to longitudinal axis (LA1) will change from thegreater radial distance presented by first portion (242); to the lesserradial distance presented by second portion (244) via intermediateportion (243); and back to the greater radial distance presented byfirst portion (242) via intermediate portion (245).

First cam (230) and second cam (240) are oriented such that firstportion (232) of first cam (230) and first portion (242) of second cam(240) are at different angular positions about shaft (222). Further,first cam (230) and second cam (240) are oriented such that secondportion (234) of first cam (230) and second portion (244) of second cam(240) are at different angular positions about shaft (222). As best seenin FIGS. 9A-9C, the radial distance of first portion (232) of first cam(230) is greater than that of first portion (242) of second cam (240).The radial distance of second portion (234) of first cam (230) isgreater than that of second portion (244) of second cant (240).

As shown in FIG. 9A-9C, follower interface feature (284) is coupled witha pivoting cam follower (290). The handle assembly comprises a pivot pin(272) to which cam follower (290) is rotatably coupled such that camfollower (290) is free to rotate about pivot pin (272). A first arm(292) of cam follower (290) is in contact with first cam (230) at a topof first cam (230) directly vertical of shaft (222) and longitudinalaxis (LA1). A second arm (294) of cam follower (290) is in contact withsecond cam (240) at a top of second cam (240) directly vertical of shaft(222) and longitudinal axis (LA1). A third arm (296) of cam follower(290) presents a slot (295). Follower interface feature (284) comprisesa pin (289) extending transversely from follower interface feature(284). Pin (289) is slidably and rotatably disposed within slot (295)such that cam follower (290) is thereby coupled with follower interfacefeature (284) and further such that, as cam follower (290) rotates aboutpivot pin (272), follower interface feature (284) translateslongitudinally. As shown in FIG. 8, a spring (274) disposed about driveractuator (264) within actuator handle assembly (270) biases followerinterface feature (284) longitudinally proximally.

As shown in FIGS. 9A and 10A, with multi-cam assembly (220) in a firstrotational position, second portion (234) of first cam (230) ispositioned above longitudinal axis (LA1). In this first rotationalposition, first arm (292) of cam follower (290) is in contact withsecond portion (234) of first cam (230). Second portion (244) of secondcam (240) is positioned toward longitudinal axis (LA1). However, secondarm (294) of cam follower (290) is not in contact with the exteriorsurface of second cam (240). With multi-cam assembly (220) in this firstrotational position, follower interface feature (284) is in a proximallongitudinal position.

As shown in FIGS. 9B and 10B, multi-cam assembly (220) is rotatedapproximately 135° to a second rotational position. In this secondrotational position, first cam (230) has been rotated such that firstportion (232) of first cam (230) is positioned above longitudinal axis(LA1) and such that first arm (292) of cam follower (290) is now incontact with first portion (232) of first cam (230). It should beunderstood that, as first cam (230) is rotated from the first rotationalposition to the second rotational position, first arm (292) of camfollower (290) is driven from the lesser radial distance presented bysecond portion (234) to the greater radial distance presented by firstportion (232) via intermediate portion (233), thus rotating cam follower(290) about pivot pin (272). Further, as cam follower (290) rotatesabout pivot pin (272), third arm (296) is also rotated, and followerinterface feature (284) is driven longitudinally distally a firstlongitudinal distance (LD1) against the proximal bias of spring (274) byrotation of third arm (296). Also in this second rotational position,second cam (240) has been rotated such that intermediate portion (243)of second cam (240) is positioned at the top of second cam (240) andsuch that second arm (294) of cam follower (290) is now in contact withintermediate portion (243) of second cam (240) in the second rotationalposition.

As shown in FIGS. 9C and 10C, multi-cam assembly (220) is rotatedapproximately a further 45° to a third rotational position. In thisthird rotational position, second cam (240) has been rotated such thatfirst portion (242) of second cam (240) is positioned above longitudinalaxis (LA1) and such that second arm (294) of cam follower (290) is nowin contact with first portion (242) of second cam (240). It shouldtherefore be understood that as second cam (240) is rotated from thefirst rotational position to the second rotational position, and then tothe third rotational position, second arm (294) of cam follower (290) isdriven from the lesser radial distance caused by contact between firstarm (292) and second portion (234) of first cam (230) to the greaterradial distance presented by first portion (242) of second cam (240) viaintermediate portion (243), thus further rotating cam follower (290)about pivot pin (272). As cam follower (290) further rotates about pivotpin (272), third arm (296) is also rotated further, and followerinterface feature (284) is driven longitudinally distally a secondlongitudinal distance (LD2) against the proximal bias of spring (274)into a distal longitudinal position. Also in this third rotationalposition, first cam (230) has been rotated such that intermediateportion (235) of first cam (230) is positioned above longitudinal axis(LAI) and such that first arm (292) of cam follower (290) is no longerin contact with first cam (230).

Further rotation of multi-cam assembly (220) will transition multi-camassembly (220) back into the first rotational position after multi-camassembly (220) completes a full 360° of rotation, thus allowing followerinterface feature (284) to be driven back into the proximal longitudinalposition. Follower interface feature (284) may be driven proximally byspring (274) as rotated cams (230, 240) provide clearance for suchproximal movement. It should be understood that proximal movement offollower interface feature (284) will cause cam follower (290) to remainin contact with multi-earn assembly (220). Translation of followerinterface feature (284) from the proximal longitudinal position to thedistal longitudinal position and back to the proximal longitudinalposition will cause the staple driver to be driven from a proximalposition to a distal position and back again via driver actuator (264).The distal motion of driver actuator (264) will deploy staples at theanastomosis site and sever excess tissue within the anastomosis; whilethe subsequent proximal motion of driver actuator will facilitateremoval of stapling head assembly (218) and anvil (240) from theanastomosis site.

It should be understood that longitudinal distances (LD1, LD2) may bemanipulated by manipulating the radial distances represented by portions(232, 234, 242, 244) of earns (230, 240) and/or arms (292, 294, 296).For instance, in the present example, first longitudinal distance (LD1)is greater than the second longitudinal distance (LD2). Differentlongitudinal distances (LD1, LD2) may impart a mechanical advantage todriver actuator (264) that varies through the full range of distalmotion of driver actuator (264). This varying mechanical advantage mayfacilitate breakage of a washer as will be described in greater detailbelow; and/or may provide other results as will be apparent to those ofordinary skill in the art in view of the teachings herein.

Intermediate portions (233, 243) and intermediate portions (234, 245)may have different contours. These different contours may representdifferent rates of change of the radial distance from the exteriorsurfaces of cams (230, 240) to longitudinal axis (LA1) presented byfirst portions (232, 242) to second portions (234, 244) and vice versa.In particular, intermediate portions (233, 243) may represent a moregradual rate of change from the radial distance presented by secondportions (234, 244) to the radial distance presented by first portions(232, 242) whereas intermediate portions (235, 245) may represent a morerapid rate of change from the radial distance presented by firstportions (232, 242) to the radial distance presented by second portions(234, 244) or vice versa depending upon which direction in which cams(230, 240) are rotated. These differing rates of change will becommunicated to follower interface feature (284), driver actuator (264),and the staple driver via cam follower (290), thus causing differingrates of longitudinal translation of follower interface feature (284),driver actuator (264), and the staple driver. For instance, intermediateportions (233, 243) may provide a relatively slow rate of distaladvancement of driver actuator (264) while intermediate portion (235,245) provides a relatively rapid rate of proximal retraction of driveractuator (264). Of course, these rates may be further varied in anysuitable way.

In some versions of instrument (200), anvil (240) contains a breakablewasher that is broken by the knife when the knife completes a fulldistal range of motion. In some instances, the washer thus provides anaudible or haptic feedback through actuator handle assembly (270) as thewasher breaks in response to completion of full advancement of the knifetoward anvil (240), though such audible/haptic feedback is notnecessary. It should be understood that the presence of the washer maypresent a sudden increase in the force required to advance driveractuator (264) distally. FIG. 24 shows an exemplary force profileencountered by driver actuator (264) during the range of distal travelof driver actuator (264). In a first range (1200) of distal motion,driver actuator (264) encounters a gradually increasing load orresisting force as the knife passes through tissue. In a second range(1210) of distal motion, driver actuator (264) encounters a spike inload or resisting force as the knife passes through the washer. In athird range (1220) of distal motion, driver actuator (264) firstencounters a sudden drop in load or resisting force after the washerbreaks, then a subsequent increase in load or resisting force asstapling head assembly (218) drives staples into anvil (240) to therebyform staples to their final height. In view of the foregoing, it shouldbe further understood that during the transition from the position shownin FIG. 9A to the position shown in FIG. 9C, the radial distancesrepresented by portions (232, 234, 242, 244) of cams (230, 240) and/orarms (292, 294, 296) may provide an increasing mechanical advantage asdriver actuator (264) reaches the end of its distal movement, therebyproviding greater force by which to break the washer and form thestaples. For instance, the knife may encounter the washer as the knifetravels through the second longitudinal distance (LD2), and themechanical advantage provided during movement through the secondlongitudinal distance (LD2) may be greater than the mechanical advantageprovided during movement through the first longitudinal distance (LD1)in order to account for increased mechanical resistance provided by thewasher forming the staples. Of course, in some versions, the breakablewasher may be omitted entirely in some versions.

B. Second Exemplary Motor and Drive Assembly with Translating CamFollower

As a variation of instrument (200) discussed above, instrument (200) maybe provided with a motor coaxially aligned with driver actuator (264).Such an arrangement is depicted in FIGS. 11A-11B, which shows exemplaryalternative components that may be incorporated into instrument (200) toactuate the staple driver and knife. In particular, FIGS. 11A-11B showan exemplary alternative motor (310) and barrel cam (320) configured tooperate substantially similar to motor (210) and barrel cam (220)discussed above except for the differences discussed below. Motor (310),barrel cam (320), and a spring (not shown) are configured to drive astapling head assembly (not shown) distally and proximally through onerevolution of barrel cam (320) via translation of a driver actuator(364) and a cam follower (384). Cam follower (384) is coupled to driveractuator (364). Driver actuator (364) of the present example isconfigured to operate substantially similar to driver actuator (64) ofinstrument (10) discussed above. In particular, a distal end of driveractuator (364) is coupled to the stapling head assembly such that driveractuator (364) actuates the stapling head assembly when motor (310)longitudinally translates driver actuator (364).

As shown in FIGS. 11A-11B, motor (310) is disposed within an actuatorhandle assembly (not shown) such that motor (310) is coaxially alignedwith driver actuator (364). In some other versions, motor (310) isoriented obliquely relative to the longitudinal axis defined by driveractuator (364). By way of example only, a merely illustrative obliquemotor orientation is described in greater detail below with reference toFIGS. 22-23. In the present example, a barrel cam (320) is coupled witha distal end of motor (310) via a shaft (3112). Motor (310) is operableto rotate barrel cam (320) about a longitudinal axis (LA2) defined bymotor (310). As shown in FIG. 11A, barrel cam (320) comprises a slopeddistal cam face (322). Sloped cam face (322) comprises a distal portion(324) and a proximal portion (326). Distal portion (324) and proximalportion (326) are disposed on radially opposite sides of barrel cam(320). Distal portion (324) presents a portion of sloped cam face (322)having a longitudinal position relative to longitudinal axis (LA2) moredistal than that of proximal portion (326), thus defining a longitudinaldistance (LD3) between distal portion (324) and proximal portion (326).Sloped cam face (322) further comprises intermediate portions (325, 327)disposed between distal portion (324) and proximal portion (326).Intermediate portions (325, 327) are contoured to provide substantiallysmooth transition between distal portion (324) and proximal portion(326) along opposite sides of barrel cam (320). Thus, at a particularpoint along sloped cam face (322) as barrel cam (320) is rotated throughone revolution, a longitudinal position of sloped cam face (322) willchange from the proximal position presented by proximal portion (326) tothe distal position presented by distal portion (324) and back again.

As shown in FIGS. 11A-11B, cam follower (384) comprises a contact prong(386) extending proximally from cam follower (384). Contact prong (386)is secured to cam follower (384) such that longitudinal translation ofcontact prong (386) causes longitudinal translation of cam follower(384). A proximal end of contact prong (386) is in contact with slopedcam face (322). Contact prong (386) is configured to remain in contactwith sloped cam face (322) as barrel cam (320) rotates. For instance, aspring (not shown) may be coaxially positioned about driver actuator(364) within the actuator handle assembly in order to bias cam follower(384) proximally such that contact prong (386) remains in contact withsloped cam face (322). Thus, as barrel cam (320) is rotated through onerevolution, a longitudinal position of cam follower (384) will translatefrom a proximal position caused by contact between the proximal end ofcontact prong (386) and proximal portion (326) of sloped cam face (322)to a distal position caused by contact between the proximal end ofcontact prong (386) and distal portion (324) of sloped cam face (322);and back again to the proximal position caused by the resilient bias ofthe spring.

FIG. 11A shows a configuration where contact prong (386) is in aproximal longitudinal position, in contact with proximal portion (326)of sloped cam face (322) of barrel cam (320). In this position, camfollower (384) is in the proximal position, and thus the staple driverremains in a proximal position. As shown in FIG. 11B, as motor (310)rotates barrel cam (320) 180°, contact prong (386) remains in contactwith sloped cam face (322) because of the proximal bias of the spring.During this rotation, contact prong (386) is transitioned viaintermediate portion (325) from proximal portion (326) to distal portion(324), and thus cam follower (384) is driven distally the distance oflongitudinal distance (LD3) to a distal longitudinal position againstthe proximal bias of the spring. As motor (310) further rotates barrelcam (320) a complete 360°, contact prong (386) remains in contact withsloped cam face (322) because of the proximal bias of the spring. Duringthis rotation, contact prong (386) is transitioned via intermediateportion (327) from distal portion (324) to proximal portion (326), suchthat the spring drives cam follower (384) proximally the distance oflongitudinal distance (LD3) into the proximal longitudinal position.Translation of cam follower (384) from the proximal longitudinalposition to the distal longitudinal position and back to the proximallongitudinal position will cause the staple driver to be driven from aproximal position to a distal position and back again via driveractuator (364).

In some versions, it may be desirable to vary the mechanical advantageimparted to cam follower (384) along longitudinal distance (LD3) throughthe range of angular travel by barrel cam (420). One merely exemplaryvariation of a barrel cam (420) is shown in FIG. 12. Barrel cam (420) isdriven by a motor (410). Barrel cam (420) comprises a variable slopedface (422) configured to operate substantially similar to barrel cam(320). In particular, barrel cam (420) and a spring (not shown) areconfigured to drive a staple driver (not shown) distally and proximallythrough one revolution of barrel cam (420) via translation of a driveractuator (464) and a cam follower (484). Variable sloped face (422)presents a series of arcuate slopes with having differing slopes andcontours which represent a series of varying advantages imparted to camfollower (484). Cam follower (484) comprises a contact prong (486).Contact prong (486) is secured to cam follower (484) such thatlongitudinal translation of contact prong (486) causes longitudinaltranslation of cam follower (484).

A proximal end of contact prong (486) is in contact with variable slopedface (422). Contact prong (486) is configured to remain in contact withsloped face (422) as variable barrel cam (420) rotates because ofproximal bias exerted by the spring upon cam follower (484). Thus, asbarrel cam (420) rotates through an entire revolution, cam follower(484) is driven longitudinally with varying mechanical advantage throughthe series of varying translation rates from a proximal position to adistal position and back to the proximal position. This varyinglongitudinal translation of cam follower (484) from the proximallongitudinal position to the distal longitudinal position and back tothe proximal longitudinal position will cause the staple driver to bedriven from a proximal position to a distal position and back again viadriver actuator (464). In the present example, motor (410) is orientedalong an axis that is parallel to the longitudinal axis defined bydriver actuator (464). However, it should be understood that motor (210)may instead be oriented obliquely relative to the longitudinal axisdefined by driver actuator (264). By way of example only, a merelyillustrative oblique motor orientation is described in greater detailbelow with reference to FIGS. 22-23.

Some versions of instrument (400) contain a breakable washer that isbroken by the knife when the knife completes a full distal range ofmotion, as discussed above with reference to FIG. 24. It will further beunderstood that the arcuate slopes of variable sloped face (422) mayprovide an increasing mechanical advantage as the knife reaches the endof its distal movement, thereby providing greater force by which tobreak the washer. Again, though, the breakable washer may be omittedentirely in some versions.

III. Exemplary Motorized Surgical Stapling Instrument with Pivoting CamFollower

FIG. 13 shows an exemplary alternative circular surgical staplinginstrument (500); while FIGS. 14-15 show a cam (520) of instrument (500)in greater detail. Instrument (500) is configured to operatesubstantially similar to instrument (200) discussed above except for thedifferences discussed below. In particular, instrument (500) may be usedto staple tissue in an annular array and sever excess tissue that isinterior to the annular array of staples to provide a substantiallysmooth transition between anastomosed tissue lumen sections. Instrument(500) comprises a motor (510) disposed within an actuator handleassembly (570) parallel to a proximal portion of a driver actuator(564). As best seen in FIG. 14, cam (520) is coupled with a distal endof motor (510) via a shaft (512). Actuation of motor (510) is configuredto cause rotation of cam (520) about a longitudinal axis (LA3) definedby motor (510). In the present example, motor (510) is oriented along anaxis that is parallel to the longitudinal axis defined by driveractuator (564). However, it should be understood that motor (510) mayinstead be oriented obliquely relative to the longitudinal axis definedby driver actuator (564). By way of example only, a merely illustrativeoblique motor orientation is described in greater detail below withreference to FIGS. 22-23.

As best seen in FIGS. 14-15, an exterior surface of cam (520) comprisesa first portion (524) and a second portion (526). First portion (524)and second portion (526) are disposed on radially opposite sides of cam(520). First portion (524) presents a portion of cam (520) having aradial distance from longitudinal axis (LA3) that is greater than aradial distance of second portion (526) from longitudinal axis (LA3).Cam (520) further comprises intermediate portions (525, 527) disposedbetween first portion (524) and second portion (526). Intermediateportions (525, 527) are contoured to provide substantially smoothtransition between first portion (524) and second portion (526) alongopposite sides of cam (520). Thus, it should be understood that, at aparticular point along the exterior surface of cam (520), as cam (520)is rotated through one revolution, a radial distance from the exteriorsurface of cam (520) to longitudinal axis (LA3) will change from thelesser radial distance presented by second portion (526) to the greaterradial distance presented by first portion (524) via intermediateportion (527) and back to the lesser radial distance presented by secondportion (526) via intermediate portion (525).

As shown in FIGS. 16A-16B, spring (574) is disposed about driveractuator (564) within actuator handle assembly (570) and biases followerinterface feature (584) longitudinally proximally. Handle assembly (570)comprises a pivot pin (572) to which a pivoting cam follower (590) isrotatably coupled such that cam follower (590) is free to rotate aboutpivot pin (572). A first arm (592) of cam follower (590) is in contactwith the exterior surface of cam (520) due to a proximal bias imposed bya spring (574) upon follower interface feature (584). A proximal end offirst arm (592) is configured to remain in contact with the exteriorsurface of cam (520) as cam (520) rotates. Thus, as cam (520) is rotatedthrough one revolution, a radial distance from the proximal end of firstarm (592) to longitudinal axis (LA3) will change from the lesser radialdistance caused by contact with second portion (526) to the greaterradial distance caused by contact with first portion (524) and back tothe lesser radial distance caused by contact with second portion (526).This change of radial distance of the distal end of first arm (592) willcause cam follower (590) to rotate about pivot pin (572) from a firstposition (FIG. 16A) to a second position (FIG. 16B) and back to thefirst position (FIG. 16A).

Follower interface feature (584) comprises a pin (589) extendingtransversely from follower interface feature (584). Pin (589) isrotatably disposed within an opening (595) formed in a second arm (594)of cam follower (590) such that cam follower (590) is thereby coupledwith follower interface feature (584) and further such that, as camfollower (590) rotates about pivot pin (572), follower interface feature(584) translates longitudinally. It should therefore be understood that,as cam (520) is rotated through one revolution, cam follower (590) isrotated from a first position to a second position and back to the firstposition, thus translating follower interface feature (584) from aproximal longitudinal position to a distal longitudinal position andback to the proximal longitudinal position due to the proximal bias fromspring (574). This longitudinal translation of follower interfacefeature (584) from the proximal longitudinal position to the distallongitudinal position and back to the proximal longitudinal positionwill cause the staple driver to be driven from a proximal position to adistal position and back again via driver actuator (564).

As shown in FIG. 16A, with cam (520) in a first rotational position,second portion (526) of cam (520) is positioned above longitudinal axis(LA3). With cam (520) in this first rotational position, the proximalend of first arm (592) of cam follower (590) is in contact with secondportion (526) of cam (520) due to the proximal bias of spring (574). Atthis stage, cam follower (590) is in the first position and followerinterface feature (584) is in a proximal position, and thus the stapledriver remains in a proximal position.

As shown in FIG. 16B, cam (520) is rotated 180° into a second rotationalposition. In this second rotational position, cam (520) has been rotatedsuch that first portion (524) of cam (520) is positioned abovelongitudinal axis (LA3) and such that the distal end of first arm (592)of cam follower (590) is now in contact with first portion (524) of cam(520). As cam (520) is rotated from the first rotational position to thesecond rotational position, first arm (592) of cam follower (590) isdriven from the lesser radial distance presented by second portion (526)to the greater radial distance presented by first portion (524) viaintermediate portion (527), thus rotating cam follower (590) about pivotpin (572). As cam follower (590) rotates about pivot pin (572), secondarm (594) is also rotated, and follower interface feature (584) isdriven longitudinally distally by rotation of second arm (594) into adistal longitudinal position.

Further rotation of cam (520)—such that cam (520) has been rotated360°—will transition cam (520) back to the first rotational position,thus allowing follower interface feature (584) to be driven proximallyback into the proximal longitudinal position due to the proximal bias ofspring (574). As previously discussed, this longitudinal translation offollower interface feature (584) from the proximal longitudinal positionto the distal longitudinal position and back to the proximallongitudinal position will cause the staple driver to be driven from aproximal position to a distal position and back again via driveractuator (564).

As best seen in FIG. 15, intermediate portion (525) and intermediateportion (527) have different contours. These different contoursrepresent different rates of change of the radial distance from theoutwardly facing caroming surface of channel (522) to longitudinal axis(LA3) presented by first portion (524) to second portion (526) and viceversa. In particular, intermediate portion (525) represents a moregradual rate of change from the radial distance presented by secondportion (526) to the radial distance presented by first portion (524)whereas intermediate portion (527) represents a more rapid rate ofchange from the radial distance presented by first portion (524) to theradial distance presented by second portion (526) or vice versadepending on the direction in which cam (520) is rotated. It should beunderstood that these differing rates of change will be communicated tofollower interface feature (584), driver actuator (564), and the stapledriver via cam follower (590) thus imparting varying mechanicaladvantage to and causing differing rates of longitudinal translation offollower interface feature (584), driver actuator (564), and the stapledriver. For instance, intermediate portion (525) may provide arelatively slow rate of distal advancement of driver actuator (564)while intermediate portion (527) provides a relatively rapid rate ofproximal retraction of driver actuator (564). Of course, these rates maybe further varied in any suitable way.

1. First Exemplary Reduced Friction Pivoting Member

It may be desirable to minimize the force require to rotate cam (520).Such a reduction in force may be accomplished by reducing the forcerequired to rotate cam follower (590) about pivoting pin (572). Onemerely exemplary variation of a reduced-friction pivoting cam follower(690) is shown in FIG. 18. Cam follower (690) is configured to operatesubstantially similar to cam follower (590) discussed above. Inparticular, cam follower (690) is configured to rotate about a pivot pinand thus longitudinally translate follower interface feature (584) as aresult of cam (520) being rotated by motor (510). Cam follower (690)comprises a first arm (692) configured to operate substantially similarto first arm (592) of cam follower (590). In particular, a distal end offirst arm (692) is configured to contact cam (520) as cam (520) rotatesto longitudinally translate driver actuator (564). A distal end of firstarm (692) of cam follower (690) presents a curved edge (693). Curvededge (693) is configured to contact the exterior surface of cam (520) ascam (520) rotates. As shown in FIG. 17, the distal end of first arm(592) of cam follower (590) from the previous example presents a flatedge (593). It should be understood that curved edge (693) of camfollower (690) may reduce the friction between cam follower (690) andcam (520) as compared with friction between flat edge (593) of camfollower (590) and cam (520).

In addition or in the alternative, the curved configuration of curvededge (693) may provide a more efficient transfer of force from cam (520)to cam follower (690). While cam (520) rotates, laterally orientedforces imparted from rotating cam (520) to flat edge (593) might be lostto friction and converted to heat, without actually causing cam follower(590) to pivot. By contrast, curved edge (693) may be able to convertsome of those same laterally oriented forces into pivoting motion of camfollower (690), by effectively receiving vertical components of thenormal force and converting the same into pivotal movement of camfollower (690). Therefore, curved edge (693) may provide a moreproductive and/or efficient transfer of force from cam (520) to camfollower (690) along a greater range of rotation of cam (520).

2. Second Exemplary Reduced Friction Pivoting Member

FIGS. 19A-19B show another merely exemplary variation of areduced-friction pivoting cam follower (790). Cam follower (790) isconfigured to operate substantially similar to cam follower (590)discussed above except for the differences discussed below. Inparticular, as shown in FIG. 19B, cam follower (790) is configured torotate about a pivot pin (772) and thus longitudinally translate afollower interface feature (784) as a result of a cam (720) beingrotated by a motor (not shown). Follower interface feature (784) isconfigured to operate substantially similar to follower interfacefeature (584) discussed above except for the differences discussedbelow. In particular, longitudinal translation of follower interfacefeature (784) causes longitudinal translation of a staple driver andknife (not shown).

Cam follower (790) comprises a first portion (792) configured to operatesubstantially similar to first arm (592) of cam follower (590) exceptfor the differences discussed below. In particular, a proximal end offirst portion (792) is associated with an exterior surface of cam (720)such that rotation of cam (720) causes rotation of cam follower (790),which in turn causes longitudinal translation of follower interfacefeature (784). A proximal end of first portion (792) of cam follower(790) presents a socket (793). A ball bearing (794) is rotatablypositioned within socket (793). Ball bearing (794) is configured tocontact the exterior surface of cam (720) as cam (720) rotates. Itshould be understood that ball bearing (794) may reduce the frictionbetween cam follower (790) and cam (720) as compared to friction betweencam follower (590) and cam (520). It should further be understood thatthe curved surface of ball bearing (794) may providing a more productiveand/or efficient transfer of force from cam (720) to cam follower (790)along a greater range of rotation of cam (720).

As also shown in FIGS. 19A-19B, a proximal end of follower interfacefeature (784) of the present example comprises a wheel (786). Wheel(786) is freely rotatable relative to follower interface feature (784).Cam follower (790) comprises a second portion (796) configured tooperate substantially similar to second arm (592) of cam follower (590)except for the differences discussed below. in particular, rotation ofcam follower (790) is configured to longitudinally translate followerinterface feature (784) via second portion (792). Second portion (796)contacts wheel (786) such that as cam follower (790) rotates, secondportion (796) will ride along and rotate wheel (786) whilesimultaneously driving follower interface feature (784) distally. Itshould be understood that wheel (786) may reduce the friction betweencam follower (790) and follower interface feature (784) as compared withfriction between cam follower (590) and follower interface feature(584).

Although the present example comprises both ball bearing (794) and wheel(786), cam follower (790) and follower interface feature (784) need notinclude both ball bearing (794) and wheel (786). For instance, someversions may include ball bearing (794) but lack wheel (786). As anothermerely illustrative example, some versions may include wheel (786) butlack ball bearing (794). Other suitable configurations and arrangementswill be apparent to those of ordinary skill in the art in view of theteachings herein.

3. Third Exemplary Reduced Friction Pivoting Member

Yet another merely exemplary variation of a reduced-friction pivotingcam follower (890) is shown in FIGS. 20A-20B. Cam follower (890) isconfigured to operate substantially similar to cam follower (590)discussed above except for the differences discussed below. Inparticular, as shown in FIG. 20B, cam follower (890) is configured torotate about a pivot pin (872) and thus longitudinally translate afollower interface feature (884) as a result of a cam (820) beingrotated by a motor (not shown). Follower interface feature (884) isconfigured to operate substantially similar to follower interfacefeature (584) discussed above except for the differences discussedbelow. In particular, longitudinal translation of follower interfacefeature (884) causes longitudinal translation of a staple driver (notshown).

Cam follower (890) comprises a first portion (892) configured to operatesubstantially similar to first arm (592) of cam follower (590) exceptfor the differences discussed below. In particular, a proximal end offirst portion (892) is associated with an exterior surface of cam (820)such that rotation of cam (820) causes rotation of cam follower (890),which in turn causes longitudinal translation of follower interfacefeature (884). A proximal end of first portion (892) of cam follower(890) of the present example is rigidly coupled to a shaft (894). Aproximal end of shaft (894) comprises a ball (896). Ball (896) isrotatably secured within a socket formed in a cylinder (898) such thatball (896) is free to rotate within cylinder (898). Cylinder (898) ispositioned to contact the exterior surface of cam (820) as cam (820)rotates such that rotation of cam (820) causes rotation of cylinder(898) about ball (896). It should be understood. that ball (896) andcylinder (898) may reduce the friction between cam follower (890) andcam (820) as compared to friction between cam follower (590) and cam(520).

As further shown in FIGS. 20A-20B, a proximal end of follower interfacefeature (884) of the present example comprises a wheel (886). Camfollower (890) comprises a second portion (899) configured to operatesubstantially similar to second arm (592) of cam follower (590) exceptfor the differences discussed below. In particular, rotation of camfollower (890) is configured to longitudinally translate followerinterface feature (884) via second portion (899). Second portion (899)contacts wheel (886) such that as cam follower (890) rotates, secondportion (899) will ride along and rotate wheel (886) whilesimultaneously driving follower interface feature (884) distally. Itshould be understood that wheel (886) may reduce the friction betweencam follower (890) and follower interface feature (884) as compared tofriction between cam follower (590) and follower interface feature(584).

Although the present example comprises ball (896), cylinder (898), andwheel (886), cam follower (890) and follower interface feature (884)need not include each of ball (896), cylinder (898), and wheel (886).For instance, some versions may include ball (896) and cylinder (898)but lack wheel (886). As another merely illustrative example, someversions may include wheel (886) but lack ball (896) and cylinder (898).Other suitable configurations and arrangements will be apparent to thoseof ordinary skill in the art in view of the teachings herein.

IV. Exemplary Motorized Circular Surgical Stapling Instrument with DualMotors

As a variation of instrument (200) discussed above, instrument (200) maybe provided with a plurality of motors. In particular, handle assembly(270) may be reconfigured to accommodate a plurality of motors toactuate the staple driver. By way of example only, a plurality of motorsmay be desirable in order to drive staples through and/or cut thick orcoarse tissue. Various examples of how instrument (200) may bereconfigured to incorporate a plurality of motors will be described ingreater detail below; while other examples will be apparent to those ofordinary skill in the art according to the teachings herein. It shouldbe understood that the examples described below may functionsubstantially similar to instrument (200) described above. Inparticular, the variations of circular surgical stapling instrument(200) described below may be used to staple tissue in an annular arrayand sever excess tissue that is interior to the annular array of staplesto provide a substantially smooth transition between lumen sections.

FIG. 21 shows exemplary alternative components that may be incorporatedinto instrument (200) to actuate the staple driver and knife. Inparticular, FIG. 21 shows a first motor (910), a second motor (912), andother components coupled with motors (910, 912). Motors (910, 912) ofthe present example may be powered by an internal power source (e.g.,battery, etc.) and/or an external power source (e.g., wall outlet,etc.). As will be discussed in more detail below, motors (910, 912) areconfigured to actuate a staple driver. The staple driver includes aplurality of staple driving members, a plurality of staples, and a knifeconfigured to sever tissue when the staple driver is actuatedlongitudinally. The staple driver of the present example functionssubstantially similar to the staple driver of instrument (200) describedabove. In particular, the staple driver of the present example may beused to drive an annular array of staples into tissue and to drive aknife (not shown) to sever excess tissue that is interior to the annulararray of staples to provide a substantially smooth transition betweenlumen sections in response to the staple driver being actuated.

A proximal end of a driver actuator (not shown) is coupled to shafts(926, 928), which are described in greater detail below, and which maybe positioned within an actuator handle assembly (not shown). A distalend of the driver actuator is coupled to the staple driver such thatlongitudinal translation of shafts (926, 928) actuates the staple drivervia the driver actuator. As will be discussed in more detail below,motors (910, 912) are operable to cause longitudinal translation ofshafts (926, 928) via a drive assembly. Thus, when motors (910, 912) areactuated and translate shafts (926, 928), the knife and the stapledriving members substantially simultaneously sever tissue and drivestaples distally into tissue.

Motors (910, 912) are disposed along different axes within the actuatorhandle assembly. Motors (910, 912) rotate their respective drive shafts(915, 917) in opposite directions. A first helical gear (914) is securedto a distal end of motor (914) via shaft (915). A second helical gear(916) is secured to a distal end of motor (912) via shaft (917). Adriven shaft (920) presents helical threading (922). Shaft (920) isdisposed within and rotatably secured to the actuator handle assemblysuch that helical threading (922) engages both first helical gear (914)and second helical gear (916). First helical gear (914) and secondhelical gear (916) engage helical threading (922) on radially oppositesides of shaft (920). A drive nut (924) is disposed about shaft (920)and engages helical threading (922) such that rotation of shaft (920)causes longitudinal translation of drive nut (924). A pair of shafts(926, 928) extends distally from drive nut (924). The distal ends ofshafts (926, 928) are secured to the driver actuator such thatlongitudinal translation of drive nut (924) causes concurrentlongitudinal translation of the driver actuator. It should therefore beunderstood that rotation of motors (910, 912) causes longitudinaltranslation of the staple driver via the driver actuator.

Motors (910, 912) may be actuated such that motors (910, 912) rotateshaft (920) in a first direction to drive shafts (926, 928) distallyfrom a proximal longitudinal position to a distal longitudinal position.Motors (910, 912) may then be reversed such that motors (910, 912)rotate shaft (920) in a second direction to drive shafts (926, 928)proximally back to the proximal longitudinal position. This longitudinaltranslation of shafts (926, 928) from the proximal longitudinal positionto the distal longitudinal position and back to the proximallongitudinal position will cause the staple driver to be driven from aproximal position to a distal position and back again via the driveractuator. Other suitable ways in which motors (910, 912) may be operatedwill be apparent to those of ordinary skill in the art in view of theteachings herein.

Exemplary Oblique Motor Orientation

Although the examples discussed above comprise a motor(s) disposedwithin an actuator handle assembly at an orientation that is parallel toa proximal portion of a driver actuator, it should be understood thatthe motor(s) may be oriented in other suitable orientation. Forinstance, as shown in FIG. 22, a motor (1010) may be disposed within anoblique pistol grip (1020) of a circular surgical stapling instrument(1000) such that motor (1010) is oriented obliquely to a longitudinalaxis defined by a driver actuator (1064). A cam (1030) is secured tomotor (1010) such that actuation of motor (1010) rotates cam (1030). Apivoting cam follower (890) rotates about a pivot pin (1072). Camfollower (890) is configured to operate substantially similar to camfollower (590) discussed above. In particular, cam follower (890) isassociated with cam (1030) and a follower interface feature (1084) suchthat rotation of cam follower (890) causes longitudinal translation offollower interface feature (1084). It should be understood that, cam(1030) could be configured in accordance with any of the cams (320, 420,520) or cam assembly (220) discussed above. It should also be understoodthat the present example is merely illustrative. Other appropriate motororientations will be apparent to those of ordinary skill in the art inview of the teachings herein.

As shown in FIG. 23, a motor (1110) may be disposed within an obliquepistol grip (1120) of a circular surgical stapling instrument (1100)such that motor (1110) is oriented obliquely to a longitudinal axisdefined by a driver actuator (1164). A first beveled gear (1112) issecured to motor (1110) such that rotation of motor (1110) causesrotation of beveled gear (1112). A second beveled gear (1114) is securedto a proximal end of cam (1140). First beveled gear (1112) and secondbeveled gear (1114) engage such that rotation of first beveled gear(1112) causes rotation of second beveled gear (1114). Rotation of motor(1110) will thus cause rotation of cam (1140). It should be understoodthat cam (1140) could be configured in accordance with any of the cams(320, 420, 520) or cam assembly (220) discussed above. It should also beunderstood that the present example is merely illustrative. Othersuitable ways of achieving oblique motor orientations will be apparentto those of ordinary skill in the art in view of the teachings herein.By way of example only, a handle assembly may provide a perpendicularlyoriented or obliquely oriented pistol grip and/or motor in accordancewith the teachings of U.S. Patent Application No. [Attorney DocketNumber END7287USNP.0606452], entitled SURGICAL STAPLER WITH ROTARY CAMDRIVE AND RETURN, filed on even date herewith, the disclosure of whichis incorporated by reference herein.

VI. Miscellaneous

In any of the examples described above, a microcontroller, ASIC, and/orother type of control module may be placed in communication with a powersource and motor (210, 310, 410, 510) and may be configured toautomatically stop motor (210, 310, 410, 510) thereby providing a way todynamically brake motor (210, 310, 410, 510) such that motor (210, 310,410, 510) may be actuated for exactly one rotation of a correspondingdrive shaft. By way of example only, such a control module may be incommunication with an encoder that is in communication with the driveshaft or some other component that moves in response to activation ofmotor (210, 310, 410, 510). As another merely illustrative example, sucha control module may be in communication with one or more reed switchesthat are in communication with the drive shaft or some other componentthat moves in response to activation of motor (210, 310, 410. 510).Other suitable types of sensors and control modules that may be used toprovide precise stopping of motor (210, 310, 410, 510) (e.g., based ontracked rotation of a component, based on translation of a component,and/or based on some other parameter, etc.) will be apparent to those ofordinary skill in the art in view of the teachings herein. Of course, acontrol module may be configured to control motor (210, 310, 410, 510)to activate for any suitable number of rotations, etc. In someinstances, controlling the starting and stopping of motor (210, 310,410, 510) may be performed in accordance with the teachings of U.S.Patent Application No. [Attorney Docket Number END72911″USNP.0606446],entitled CONTROL FEATURES FOR MOTORIZED SURGICAL STAPLING INSTRUMENT,filed on even date herewith, the disclosure of which is incorporated byreference herein.

It should be understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Theabove-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

At least some of the teachings herein may be readily combined with oneor more teachings of U.S. Pat. No. 7,794,475, entitled “Surgical StaplesHaving Compressible or Crushable Members for Securing Tissue Therein andStapling Instruments for Deploying the Same,” issued Sep. 14, 2010, thedisclosure of which is incorporated by reference herein; U.S. patentapplication Ser. No. 13/693,430, entitled “Trans-Oral Circular AnvilIntroduction System with Dilation Feature,” filed Dec. 4, 2012, thedisclosure of which is incorporated by reference herein; U.S. patentapplication Ser. No. 13/688,951, entitled “Surgical Staple with IntegralPledget for Tip Deflection,” filed Nov. 29, 2012, the disclosure ofwhich is incorporated by reference herein; U.S. patent application Ser.No. 13/706,827, entitled “Surgical Stapler with Varying Staple Widthsalong Different Circumferences,” filed Dec. 6, 2012, the disclosure ofwhich is incorporated by reference herein; U.S. patent application Ser.No. 13/688,992, entitled “Pivoting Anvil for Surgical Circular Stapler,”filed Nov. 29, 2012, the disclosure of which is incorporated byreference herein; U.S. patent application Ser. No. 13/693,455, entitled“Circular Anvil Introduction System with Alignment Feature,” filed Dec.4, 2012, the disclosure of which is incorporated by reference herein;U.S. patent application Ser. No. 13/716,313, entitled “Circular Staplerwith Selectable Motorized and Manual Control, Including a Control Ring,”filed Dec. 17, 2012, the disclosure of which is incorporated byreference herein; U.S. patent application Ser. No. 13/716,318, entitled“Motor Driven Rotary Input Circular Stapler with Modular End Effector,”filed Dec. 17, 2012, the disclosure of which is incorporated byreference herein; and/or U.S. patent application Ser. No. 13/176,323,entitled “Motor Driven Rotary Input Circular Stapler with LockableFlexible Shaft,” filed Dec. 17, 2012, the disclosure of which isincorporated by reference herein. Various suitable ways in which suchteachings may be combined will be apparent to those of ordinary skill inthe art.

While the examples herein have been provided in the context of acircular stapling instrument, it should be understood that the variousteachings herein may be readily applied to various other kinds ofsurgical instruments. By way of example only, the various teachingsherein may be readily applied to linear stapling devices (e.g.,endocutters). For instance, various teachings herein may be readilycombined with various teachings of U.S. Pub. No. 2012/0239012, entitled“Motor-Driven Surgical Cutting Instrument with Electric ActuatorDirectional Control Assembly,” published. Sep. 20, 2012, the disclosureof which is incorporated by reference herein, and/or U.S. Pub. No.2010/0264193, entitled “Surgical Stapling Instrument with AnArticulatable End Effector,” published Oct. 21, 2010, the disclosure ofwhich is incorporated by reference herein, as will be apparent to thoseof ordinary skill in the art. As another merely illustrative example,the various teachings herein may be readily applied to a motorizedelectrosurgical device. For instance, various teachings herein may bereadily combined with various teachings of U.S. Pub. No. 2012/0116379,entitled “Motor Driven Electrosurgical Device with Mechanical andElectrical Feedback,” published May 10, 2012, the disclosure of which isincorporated by reference herein, as will be apparent to those ofordinary skill in the art. Other suitable kinds of instruments in whichthe teachings herein may be applied, and various ways in which theteachings herein may be applied to such instruments, will be apparent tothose of ordinary skill in the art.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may have application inconventional medical treatments and procedures conducted by a medicalprofessional, as well as application in robotic-assisted medicaltreatments and procedures. By way of example only, various teachingsherein may be readily incorporated into a robotic surgical system suchas the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale, Calif.

Versions described above may be designed to be disposed of after asingle use, or they can be designed to be used multiple times. Versionsmay, in either or both cases, be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, someversions of the device may be disassembled, and any number of theparticular pieces or parts of the device may be selectively replaced orremoved in any combination. Upon cleaning and/or replacement ofparticular parts, some versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a userimmediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

1-20. (canceled)
 21. A surgical instrument comprising: (a) a body; (b) ashaft extending distally from the body, wherein the shaft comprises aproximal end and a distal end; (c) a stapling assembly, wherein thestapling assembly is disposed at the distal end of the shaft, whereinthe stapling assembly is operable to drive a plurality of staples intotissue; (d) a motor; (e) a cam assembly coupled with the motor andincluding a first cam portion and a second cam portion, wherein themotor is operable to rotate the first and second cam portions; and f) afiring assembly having a distal firing portion operatively coupled withthe stapling assembly, wherein the distal firing portion is configuredto move distally from a proximal position to a distal position andthereby drive movement of the stapling assembly, wherein the first andsecond cam portions are configured to sequentially engage the firingassembly during rotation of the cam assembly relative to the firingassembly such that: (i) the first cam portion drives the distal firingportion distally toward the distal position through a first segment oflongitudinal travel, and (ii) the second cam portion drives the distalfiring portion further distally toward the distal position through asecond segment of longitudinal travel that extends distally from thefirst segment of longitudinal travel, wherein the first and secondsegments of longitudinal travel differ in length.
 22. The surgicalinstrument of claim 21, wherein the firing assembly includes a followermember operatively coupled to the body and to the distal firing portion,wherein the follower member includes a first follower portion and asecond follower portion, wherein the first cam portion is configured tocontact the first follower portion to drive the distal firing portionthrough the first segment of longitudinal travel, wherein the second camportion is configured to contact the second follower portion to drivethe distal firing portion through the second segment of longitudinaltravel.
 23. The surgical instrument of claim 22, wherein the followermember is pivotably coupled to the body about a pivot axis, wherein thefollower member is configured to pivot about the pivot axis when thefirst cam portion contacts the first follower portion and thereby drivethe distal firing portion distally through the first segment oflongitudinal travel.
 24. The surgical instrument of claim 22, whereinthe first follower portion comprises a first arm extending toward thefirst cam portion, wherein the second follower portion comprises asecond arm extending toward the second cam portion.
 25. The surgicalinstrument of claim 21, wherein the cam assembly comprises a first camand a second cam, wherein the first cam includes the first cam portion,wherein the second cam includes the second cam portion.
 26. The surgicalinstrument of claim 25, wherein the first and second cams are spacedapart longitudinally along a shaft driven by the motor.
 27. The surgicalinstrument of claim 21, wherein the first and second cam portions arearranged on a shaft and extend radially outwardly from a longitudinalaxis defined by the shaft, wherein the first and second cam portions arelongitudinally spaced from one another along the longitudinal axis. 28.The surgical instrument of claim 27, wherein the first cam portionincludes an outermost radial end defining a maximum radial dimension ofthe first cam portion relative to the longitudinal axis, wherein thesecond cam portion includes an outermost radial end defining a maximumradial dimension of the second cam portion relative to the longitudinalaxis, wherein the outermost radial ends of the first and second camportions are angularly offset from one another about the longitudinalaxis.
 29. The surgical instrument of claim 21, wherein the first segmentof longitudinal travel is longer than the second segment of longitudinaltravel.
 30. The surgical instrument of claim 21, wherein the camassembly is configured to drive the distal firing portion distally fromthe proximal position to the distal position by rotation of the camassembly through a single revolution.
 31. The surgical instrument ofclaim 21, further comprising a resilient member configured to bias thefiring assembly proximally into engagement with the cam assembly. 32.The surgical instrument of claim 21, wherein the first cam portion isconfigured to drive the distal firing portion distally through the firstsegment of longitudinal travel with a first force, wherein the secondcam portion is configured to drive the distal firing portion distallythrough the second segment of longitudinal travel with a second force,wherein the first and second forces differ in magnitude.
 33. Thesurgical instrument of claim 21, wherein the first cam portion includesa first contoured face, wherein the second cam portion includes a secondcontoured face, wherein the first and second contoured faces areconfigured to contact the firing assembly.
 34. The surgical instrumentof claim 21, wherein the cam assembly comprises a barrel cam, whereinthe barrel cam includes the first cam portion and the second camportion.
 35. The surgical instrument of claim 21, wherein the staplerassembly is operable to drive a plurality of staples in a circular arrayto secure together first and second lumens of tissue.
 36. A surgicalinstrument comprising: (a) a body; (b) a shaft extending distally fromthe body, wherein the shaft comprises a proximal end and a distal end;(c) a stapling assembly, wherein the stapling assembly is disposed atthe distal end of the shaft, wherein the stapling assembly is operableto drive a plurality of staples into tissue; (d) a motor; (e) a camassembly coupled with the motor and including a first cam and a secondcam, wherein the motor rotates the first and second cams; and (f) afiring assembly having a distal firing portion operatively coupled withthe stapling assembly, wherein the distal firing portion is configuredto move distally from a proximal position to a distal position andthereby drive movement of the stapling assembly, wherein the first andsecond cams are configured to sequentially engage the firing assemblyduring rotation of the cam assembly such that: (i) the first cam drivesthe distal firing portion distally with a first force through a firstsegment of longitudinal travel, and (ii) the second cam drives thedistal firing portion distally with a second force through a secondsegment of longitudinal travel that extends distally from the firstsegment of longitudinal travel, wherein the second force differs inmagnitude from the first force.
 37. The surgical instrument of claim 36,wherein the second force is greater in magnitude than the first force.38. The surgical instrument of claim 36, wherein the firing assemblyincludes a follower member operatively coupled to the body and to thedistal firing portion, wherein the follower member includes a firstfollower portion and a second follower portion, wherein the first cam isconfigured to contact the first follower portion to drive the distalfiring portion distally through the first segment of longitudinaltravel, wherein the second cam is configured to contact the secondfollower portion to drive the distal firing portion distally through thesecond segment of longitudinal travel.
 39. A surgical instrumentcomprising: (a) a body; (b) a shaft extending distally from the body,wherein the shaft comprises a proximal end and a distal end; (c) astapling assembly, wherein the stapling assembly is disposed at thedistal end of the shaft, wherein the stapling assembly is operable todrive a plurality of staples into tissue; (d) a motor; (e) a cam mountedon a shaft rotated by the motor; and (f) a firing assembly operativelycoupled with the stapling assembly, wherein the firing assemblyincludes: (i) an actuating member extending distally toward the staplingassembly, wherein the actuating member is configured to move distallyfrom a proximal position to a distal position and thereby cause thestapling assembly to drive staples into tissue, (ii) a follower memberpivotably coupled to the body about a pivot axis and operatively coupledto a proximal end of the actuating member, wherein the follower memberhas a proximal end that engages the cam, wherein the motor is operableto rotate the cam to cause the follower member to pivot about the pivotaxis and thereby drive the actuating member toward the distal position,and (iii) a friction reducing member arranged at the proximal end of thefollower member, wherein the friction reducing member comprises a curvedsurface that engages the cam.
 40. The surgical instrument of claim 39,wherein the friction reducing member comprises a rotating member,wherein the rotating member is configured to rotate relative to the camand the follower member when the cam is rotated by the motor.